The search for a new ampere standard has moved a little further on, with a paper claiming that accurate quantum-level electron generation is feasible.
Hans Schumacher of the Federal Institute of Physical and Technical Affairs (PTB) in Braunschweig, Germany, and a group of collaborators, say they have been able to demonstrate “ …

Re: Nail that Electron

Have to be careful with that. Otherwise you'll blow out a good portion of your EPS grid the first time you use the transporter afterward and noone wants that, especially not anyone who might be caught in the buffer at the time.

Re: Nail that Electron

Reroute the EPS flow through secondary relays and cycle the pattern through the cargo pad buffers. Once there, you should be able to get a lock on the pattern in the cargo pad buffers by using a second annular confinement beam.

Just make sure you track both beams and re-integrate them, otherwise you'll clone whatever's in the buffer.

a little harsh

"joking or senile" seems a bit excessive.

Perhaps the point being made is that its easier to count electrons (eg Millikan's oil drop experiment, which wasn't that easy at the time but should in some form straightforward be today) and measure their charge statically. Then you just need mu_0 and epsilon_0, bingo, Ampere's law gives you the definition of an Amp as quoted. I'm guessing that this plan is why the definitions were set up the way they were.

If I understand this correctly, what they are doing here is coming up with a way of counting electrons accurately. As a coulomb is equal to the charge on a fixed (& very large) number of electrons, surely this will lead to defining the ampere in terms of the coulomb?

Thanks for that. I was just pointing out that the coulomb would make a better base unit than the ampere. It's interesting that they're striving to define the kilogram by counting standard isotope silicone atoms much in the same way counting electrons could give a better definition of the coulomb...

Re: Hmmm

The electrons will almost certainly never arrive at your house, what with them wobbling back and forth all the time. Power will arrive at your house, but the electrons you started with are still the ones you've got today.

quantum metrologists

Redefining the Ampere standard biggest change since Josephson got in on the Volt act.

...the amount of charge flowing per second through two infinitely long wires one meter apart,..

Well, perhaps we should put Maxwell's demon down amongst the electrons to count 'em. ;-)

Seriously, that definition of the Ampere always seemed to be messy to me. Seems that if the standard ampere is changed then there'll have to be some tinkering with the Volt definition too as it is also defined in terms of the same parallel wires in free space as well as a more practical/measurable (and precise) standard--that's now defined by the Josephson junction (which is some 4 orders of magnitude better than the old Weston cell standard of 1.434 volts).

If it can be done then it makes sense to count electrons this way as it does to measure frequency from a Josephson junction for the Volt standard (frequency [time] being the most precise measurement standard we have devised so far). Hopefully, come the change, this would put Ampere standard on par with that of the Volt.

Except for the Ampere measurement, I'd reckon there'd be no change to the related maths (as with the Volt, the parallel wires defn. would also remain).